rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=73ac/1/0x4000000000000000 softirq=0/0 fqs=0 rcuc=10500 jiffies(starved) rcu: (t=10500 jiffies g=22553 q=346 ncpus=2) rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g22553 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=18551 rcu: rcu_preempt kthread starved for 10500 jiffies! g22553 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:21688 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 CPU: 0 UID: 0 PID: 5801 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xec1/0x12b0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 f8 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 33 93 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 17 93 RSP: 0018:ffffc900045c7580 EFLAGS: 00000293 RAX: ffffffff81b46959 RBX: 1ffff11017128525 RCX: ffff888033f5dac0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900045c7700 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1db3a4f R12: ffff8880b8942928 R13: dffffc0000000000 R14: ffff8880b883c780 R15: 0000000000000001 FS: 000055557ea51500(0000) GS:ffff888126d69000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9601365d58 CR3: 000000004bd48000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x6b1/0x1280 arch/x86/mm/tlb.c:1472 dup_mmap+0x15bb/0x1ae0 mm/mmap.c:1873 dup_mm kernel/fork.c:1486 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1538 copy_process+0x1665/0x3960 kernel/fork.c:2178 kernel_clone+0x21d/0x7a0 kernel/fork.c:2608 __do_sys_clone kernel/fork.c:2749 [inline] __se_sys_clone kernel/fork.c:2733 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2733 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe043345e93 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007fff6d5461e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe043345e93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055557ea517d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 00000000000579e0 R15: 00007fff6d546380 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:num_possible_cpus include/linux/cpumask.h:1220 [inline] RIP: 0010:mm_get_cid+0xab/0x130 kernel/sched/sched.h:3759 Code: 41 5c 41 5d 41 5e 41 5f 5d e9 91 68 35 09 cc 49 c7 c5 c8 24 00 8d 49 c1 ed 03 bd 00 00 00 80 eb 07 44 89 f0 f7 d8 71 d4 f3 90 <43> 0f b6 44 25 00 84 c0 75 41 44 8b 3d 0c 07 6e 0b 48 89 df 4c 89 RSP: 0018:ffffc900001d7b88 EFLAGS: 00000887 RAX: 0000000080000000 RBX: ffff8880360c5890 RCX: 1ffff11004d97e0c RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff8880360c5890 RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed1006c18ae3 R12: dffffc0000000000 R13: 1ffffffff1a00499 R14: 0000000080000000 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888126e69000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b9c9bcf98 CR3: 0000000052208000 CR4: 00000000003526f0 Call Trace: mm_cid_from_cpu kernel/sched/sched.h:3820 [inline] mm_cid_schedin kernel/sched/sched.h:3870 [inline] mm_cid_switch_to kernel/sched/sched.h:3886 [inline] context_switch kernel/sched/core.c:5245 [inline] __schedule+0x2153/0x50a0 kernel/sched/core.c:6863 schedule_idle+0x52/0x90 kernel/sched/core.c:6986 do_idle+0x4b3/0x520 kernel/sched/idle.c:360 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147 watchdog: BUG: soft lockup - CPU#0 stuck for 226s! [syz-executor:5801] Modules linked in: irq event stamp: 2055318 hardirqs last enabled at (2055317): [] irqentry_exit+0x5dd/0x660 kernel/entry/common.c:219 hardirqs last disabled at (2055318): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056 softirqs last enabled at (2003834): [] __local_bh_enable_ip+0x1b3/0x2e0 kernel/softirq.c:305 softirqs last disabled at (2003828): [] local_bh_disable include/linux/bottom_half.h:20 [inline] softirqs last disabled at (2003828): [] spin_lock_bh include/linux/spinlock_rt.h:87 [inline] softirqs last disabled at (2003828): [] release_sock+0x2f/0x210 net/core/sock.c:3793 CPU: 0 UID: 0 PID: 5801 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xec1/0x12b0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 f8 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 33 93 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 17 93 RSP: 0018:ffffc900045c7580 EFLAGS: 00000293 RAX: ffffffff81b46959 RBX: 1ffff11017128525 RCX: ffff888033f5dac0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900045c7700 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1db3a4f R12: ffff8880b8942928 R13: dffffc0000000000 R14: ffff8880b883c780 R15: 0000000000000001 FS: 000055557ea51500(0000) GS:ffff888126d69000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9601365d58 CR3: 000000004bd48000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x6b1/0x1280 arch/x86/mm/tlb.c:1472 dup_mmap+0x15bb/0x1ae0 mm/mmap.c:1873 dup_mm kernel/fork.c:1486 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1538 copy_process+0x1665/0x3960 kernel/fork.c:2178 kernel_clone+0x21d/0x7a0 kernel/fork.c:2608 __do_sys_clone kernel/fork.c:2749 [inline] __se_sys_clone kernel/fork.c:2733 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2733 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe043345e93 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007fff6d5461e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe043345e93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055557ea517d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 00000000000579e0 R15: 00007fff6d546380 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:num_possible_cpus include/linux/cpumask.h:1220 [inline] RIP: 0010:mm_get_cid+0xb1/0x130 kernel/sched/sched.h:3759 Code: 41 5f 5d e9 91 68 35 09 cc 49 c7 c5 c8 24 00 8d 49 c1 ed 03 bd 00 00 00 80 eb 07 44 89 f0 f7 d8 71 d4 f3 90 43 0f b6 44 25 00 <84> c0 75 41 44 8b 3d 0c 07 6e 0b 48 89 df 4c 89 fe e8 49 d5 e7 02 RSP: 0018:ffffc900001d7b88 EFLAGS: 00000887 RAX: 0000000000000000 RBX: ffff8880360c5890 RCX: 1ffff11004d97e0c RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff8880360c5890 RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed1006c18ae3 R12: dffffc0000000000 R13: 1ffffffff1a00499 R14: 0000000080000000 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888126e69000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b9c9bcf98 CR3: 0000000052208000 CR4: 00000000003526f0 Call Trace: mm_cid_from_cpu kernel/sched/sched.h:3820 [inline] mm_cid_schedin kernel/sched/sched.h:3870 [inline] mm_cid_switch_to kernel/sched/sched.h:3886 [inline] context_switch kernel/sched/core.c:5245 [inline] __schedule+0x2153/0x50a0 kernel/sched/core.c:6863 schedule_idle+0x52/0x90 kernel/sched/core.c:6986 do_idle+0x4b3/0x520 kernel/sched/idle.c:360 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147